The GRAVITY+ Project: Towards All-sky, Faint-Science, High-Contrast Near-Infrared Interferometry at the VLTI

The GRAVITY instrument has been revolutionary for near-infrared interferometry by pushing sensitivity and precision to previously unknown limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) in GRAVITY+, these limits will be pushed even further, with vastly improved sky coverage, as well as faint-science and high-contrast capabilities. This upgrade includes the implementation of wide-field off-axis fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser guide stars in an upgraded facility. GRAVITY+ will open up the sky to the measurement of black hole masses across cosmic time in hundreds of active galactic nuclei, use the faint stars in the Galactic centre to probe General Relativity, and enable the characterisation of dozens of young exoplanets to study their formation, bearing the promise of another scientific revolution to come at the VLTI.Comment: Published in the ESO Messenge

Author correction : roadmap for naming uncultivated archaea and bacteria

Correction to: Nature Microbiology https://doi.org/10.1038/s41564-020-0733-x , published online 8 June 2020. In the version of this Consensus Statement originally published, Pablo Yarza was mistakenly not included in the author list. Also, in Supplementary Table 1, Alexander Jaffe was missing from the list of endorsees. These errors have now been corrected and the updated Supplementary Table 1 is available online

Roadmap for naming uncultivated Archaea and Bacteria

The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as ‘type material’, thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code for uncultivated Archaea and Bacteria that could eventually be merged with the ICNP in the future. Regardless of the path taken, we believe that action is needed now within the scientific community to develop consistent rules for nomenclature of uncultivated taxa in order to provide clarity and stability, and to effectively communicate microbial diversity

La mise en oeuvre de la directive "droits des actionnaires" (SRD I et II) au Luxembourg

editorial reviewed9. Industry, innovation and infrastructur

La titrisation

Faisant figure d'innovation parmi les plus marquantes du droit bancaire et financier luxembourgeois, la loi du 22 mars 2004 relative à la titrisation connaît un grand succès. Le présent ouvrage propose d'en découvrir l'approche originale autant que les solutions techniques, sans toutefois la soustraire à un examen critique. Une perspective transversale axée sur les fondements de la loi s'y conjugue avec des éclairages ciblés sur le régime des organismes de titrisation, les mécanismes particuliers de protection contre la faillite et le traitement fiscal. Une étude conceptuelle et pratique destinée à tous ceux qui souhaitent se familiariser avec une technique performante et sophistiquée

The New Luxembourg Company Law

Sommaire : Introduction par André Prüm Les lignes de force des récentes réformes : vers un droit commun des personnes morales de droit privé par Isabelle Corbisier Les organes de la société anonyme (SA) en droit luxembourgeois par Pierre-Henri Conac Les restructurations d’entreprises par Jean-Paul Spang Le transfert de patrimoine professionnel. Une contribution helvétique au droit des sociétés luxembourgeois par Rashid Bahar La société anonyme unipersonnelle par Alain Couret La mobilité des sociétés par Daniel Ruppert Le projet de refonte globale du droit des sociétés par André Prüm Quelques réflexions en guise de conclusion par Pierre Van Ommeslagh

Implementation of the chromatic phase diversity method on the SIRIUS test bench

International audienc

Aerosol and cloud top height information of Envisat MIPAS measurements

Infrared limb emission instruments have a long history in measuring clouds and aerosol. In particular, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument aboard ESA's Envisat provides 10 years of altitude-resolved global measurements. Previous studies found systematic overestimations and underestimations of cloud top heights for cirrus and polar stratospheric clouds. To assess the cloud top height information and to characterise its uncertainty for the MIPAS instrument we performed simulations for ice clouds, volcanic ash, and sulfate aerosol. From the simulation results we found that in addition to the known effects of the field-of-view that can lead to a cloud top height overestimation, and broken cloud conditions that can lead to underestimation, the cloud extinction also plays an important role. While for optically thick clouds the possible cloud top height overestimation for MIPAS reaches up to 1.6 km due to the field-of-view, for optically thin clouds and aerosol the systematic underestimation reaches 5.1 km. For the detection sensitivity and the degree of underestimation of the MIPAS measurements, the cloud layer thickness also plays a role; 1 km thick clouds are detectable down to extinctions of 5×10−4 km−1 and 6 km thick clouds are detectable down to extinctions of 1×10−4 km−1, where the largest underestimations of the cloud top height occur for the optically thinnest clouds with a vertical extent of 6 km. The relation between extinction coefficient, cloud top height estimate, and layer thickness is confirmed by a comparison of MIPAS cloud top heights of the volcanic sulfate aerosol from the Nabro eruption in 2011 with space- and ground-based lidar measurements and twilight measurements between June 2011 and February 2012. For plumes up to 2 months old, where the extinction was between 1×10−4 and 7×10−4 km−1 and the layer thickness mostly below 4 km, we found for MIPAS an average underestimation of 1.1 km. In the aged plume with extinctions down to 5×10−5 km−1 and layer thicknesses of up to 9.5 km, the underestimation was higher, reaching up to 7.2 km. The dependency of the cloud top height overestimations or underestimations on the extinction coefficient can explain seemingly contradictory results of previous studies. In spite of the relatively large uncertainty range of the cloud top height, the comparison of the detection sensitivity towards sulfate aerosol between MIPAS and a suite of widely used UV/VIS limb and IR nadir satellite aerosol measurements shows that MIPAS provides complementary information in terms of detection sensitivity